A motor vehicle controller configured to reduce net drive torque applied to one or more driving wheels of a first axle of a driveline when an amount of slip of a driving wheel of the first axle exceeds a first predetermined threshold value. The controller controls torque applied to wheels of a second axle and determines when the vehicle is operating in a split-mu condition in which slip of a driving wheel on one side of each of the two axles exceeds that of a driving wheel on an opposite side of the axles by more than a predetermined amount. The controller performs a split-mu mitigation operation by reducing net torque applied to a driving wheel of the axle that is experiencing the greater slip when an amount of slip of that driving wheel exceeds a second predetermined threshold value less than the first predetermined threshold value.